The present invention relates to a collating machine and more particularly to a collating machine having the dual capability of stacking sheets of paper in the same or reverse order in which they are fed to the collating machine.
Collating machines are frequently used in line with other paper handling equipment, such as inserting machines, as a means of assembling a plurality of sheets of paper into a particular, desired packet prior to further processing, which may include additional collating, folding and inserting. For further background, reference can be made to U.S. Pat. Nos. 3,935,429, 4,547,856 and U.S. Pat. No. 4,733,359. In a typical paper handling sequence involving an initial output consisting of a plurality of sheets of paper, which may later be combined with subsequent outputs from other sheet feeding devices situated downstream, the initial output is fed from a stack seriatim to the collator, which collates the output into the desired packets, either in the same order as the sheets had when they were in the stack upstream of the collator or in the reverse order. Each packet may then be folded, stitched or subsequently combined with other outputs from document feeding devices located downstream thereof and ultimately inserted into a mailing envelope.
In many cases it happens that the initial output to be collated arrives in an opposite order from that desired for downstream processing so that the collator needs to collate in an opposite manner to enable the documents to emerge from the collator in the proper sequence for subsequent handling. In such a case, one option is to have a second line of paper handling equipment which includes a collator having reverse collating capability. Clearly, this is not a desirable option to users of pape handling equipment. An improvement over the second line option is offered in U.S. Pat. No. 4,640,506, issued Feb. 3, 1987 to the assignee of the present application, which teaches the incorporation in the collating machine of removable reverse order stacking devices. It has been found that incorporating and removing machine parts requires time and effort which is very costly for complex equipment, such as an inserter, which can afford little down time. A further improvement over the removable devices, is disclosed in U.S. Pat. No. 4,805,891, issued Feb. 21, 1989 to the assignee of the present invention, which teaches a movable device in a collating machine, which can easily be moved by an operator from one position to another to change from standard sequence stacking to reverse sequence stacking. The movable device has worked well for collating in the reverse order, however problems have been experienced when switching from reverse to standard order collation. Additional adjustments requiring the use of tools by a service technician have been necessary to change from reverse to standard stacking of collations. Accordingly, the present invention provides an improvement to the movable reverse order collating device which improves the reliability of an operator changing the machine to collate from reverse to standard order.